The downward force (gravity) exerted on a gantry by the weight of the router whilst in the middle Y position would be almost negligable compared to: (a) the upward force caused during a pierce in aluminium or (b) the frontwards/ backwards forces and/or twisting forces exerted upon the gantry during cutting of say MDF where sometimes you have big diameter tools + fast travel speed + thick material. If the gantry sags when the router motor is at middle Y point then I'd hate to imagine how unaccurate the cut parts would be due to the flex in other directions. The only exception to the above would be if one had used a profile (for the gantry) where the width was much wider than the height. (5" wide x 0.5" high for example) Yes, in case there would be minimal front/back flex but an unacceptable amount of up/down and twist movement. (i.e. poor choice of material size). A rectangular section aluminium profile that is correctly sized in the first place is the cheapest and strongest method rather than thinking about beefing up other methods which aren't strong enough in the first place.
Skippy
Last edited by skippy; 03-15-2005 at 12:02 PM.
Reason: addition
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